I thought factory chambers were all really long?

I will start by saying that I've only been reloading for 2 years and my latest rifle (model 10 LE FCP HS Precision stock)is my first jump into long range shooting so my reloading techniques and equipment have needed some upgrades. I measured my chamber by taking 3 cases and full length sizing them(trimming,chamfer.etc.) then slotting the neck with 4 slots from a dremel cutoff wheel. I used a sinclair bullet comparator to measure 3 bullets(Sierra 168gr HPBT) so that I knew that they had the same base to ogive length and seated them lightly into the modified cases. I then carefully put them into the chamber and closed the bolt and carefully opened it up and retrieved the case which now had the bullet seated to the lands. I repeated this measurement 3 times and averaged it out, the base of cartridge to ogive (the calipers were zeroed on the comparator) measured 2.109". The total overall length of the cartridge from base to tip average was 2.808". I repeated this test in the exact same manner with 175gr HPBT and the results were; base to ogive average 2.110" and the COAL average was 2.816". All of my manuals have the COAL at 2.800" but I was expecting to have to exceed that to get the bullet closer to the lands. I am using a Forster bullet seating die so I'm more interested in the base to ogive measurement than COAL. Did I somehow mess these chamber measurements up? Is this normal for a Savage chamber? I guess I was expecting something more like 2.950".

Steve

One thing that you need to be careful with is using FL resized cases with the ejector still installed in the gun.

If you resize the cases and push the shoulder back and the ejector is still installed in the bolt, the ejector may be pushing the short case into the chamber and giving you a short reading.

To check this, remove the ejector from your bolt and see if the measurement is the same.

All chambers either factory or custom gunsmith vary with the age of the reamer. Brand new reamers will cut a large, long chamber and a reamer that has been used dozens of times and resharpened numerous times will cut a tight chamber.

uj

I just repeated everything only I used fireformed brass that I necksized only. I then trimmed,chamfered,etc and then slotted the cases. I got almost the exact same results (it was .001" different) that I got with the FL sized cases so I at least feel good about my die setup. I did this with the 168gr SMK and didn't bother to do the 175gr. I may try it without the extractor though, just to be absolutely certain. I'm not really upset about this as it makes my load development a little less complicated, since I really don't have the option of a long jump. It's going to be either a short jump or no jump, guess I better watch for pressure signs.

Steve

Steve,

In my Savage 10 FP .308 the COAL to reach the lands with 168gr SMK is 2.815". In my Rem 700 it is 2.947".

Steve, count yourself one of the lucky ones then. It looks like you got a closer to spec chamber than most people.

My 10fp in 308 is very similar to yours, on the short side, my 116 in 7 mag is like this also, but all of my 223s and 22-250s have to be loaded longer than than the max OAL listed to get the bullets close to the lands.

Mike

Thanks guys , I was worried I screwed something up. I'm good with it now and I do feel lucky.

Steve